Add note about marking Cocoa APIs that take references to objects but don't retain them.
Add note about marking Cocoa APIs that take references to objects but don't retain them.

Swift SVN r4371

emilstahl/swift,brentdax/swift,manavgabhawala/swift,brentdax/swift,huonw/swift,gribozavr/swift,karwa/swift,natecook1000/swift,kstaring/swift,alblue/swift,practicalswift/swift,MukeshKumarS/Swift,ben-ng/swift,ben-ng/swift,JaSpa/swift,swiftix/swift,swiftix/swift.old,xwu/swift,codestergit/swift,deyton/swift,tjw/swift,allevato/swift,kusl/swift,devincoughlin/swift,airspeedswift/swift,xedin/swift,mightydeveloper/swift,stephentyrone/swift,emilstahl/swift,gribozavr/swift,atrick/swift,cbrentharris/swift,zisko/swift,ken0nek/swift,Ivacker/swift,danielmartin/swift,tjw/swift,glessard/swift,therealbnut/swift,hooman/swift,jckarter/swift,khizkhiz/swift,sdulal/swift,CodaFi/swift,benlangmuir/swift,emilstahl/swift,atrick/swift,LeoShimonaka/swift,glessard/swift,nathawes/swift,practicalswift/swift,jckarter/swift,shahmishal/swift,gmilos/swift,apple/swift,ken0nek/swift,jtbandes/swift,dreamsxin/swift,adrfer/swift,karwa/swift,sdulal/swift,parkera/swift,lorentey/swift,SwiftAndroid/swift,KrishMunot/swift,apple/swift,mightydeveloper/swift,dduan/swift,djwbrown/swift,swiftix/swift.old,brentdax/swift,tinysun212/swift-windows,nathawes/swift,calebd/swift,shajrawi/swift,KrishMunot/swift,tardieu/swift,harlanhaskins/swift,deyton/swift,OscarSwanros/swift,practicalswift/swift,manavgabhawala/swift,felix91gr/swift,deyton/swift,xedin/swift,djwbrown/swift,Jnosh/swift,swiftix/swift,gottesmm/swift,xwu/swift,LeoShimonaka/swift,gottesmm/swift,ben-ng/swift,return/swift,gmilos/swift,adrfer/swift,therealbnut/swift,swiftix/swift,hughbe/swift,apple/swift,tinysun212/swift-windows,sschiau/swift,djwbrown/swift,parkera/swift,milseman/swift,xwu/swift,slavapestov/swift,lorentey/swift,shajrawi/swift,Jnosh/swift,cbrentharris/swift,austinzheng/swift,mightydeveloper/swift,atrick/swift,cbrentharris/swift,natecook1000/swift,harlanhaskins/swift,xedin/swift,tinysun212/swift-windows,swiftix/swift.old,hooman/swift,gregomni/swift,allevato/swift,russbishop/swift,dreamsxin/swift,brentdax/swift,SwiftAndroid/swift,SwiftAndroid/swift,MukeshKumarS/Swift,therealbnut/swift,parkera/swift,adrfer/swift,karwa/swift,shahmishal/swift,swiftix/swift,emilstahl/swift,aschwaighofer/swift,alblue/swift,djwbrown/swift,arvedviehweger/swift,sdulal/swift,shajrawi/swift,swiftix/swift.old,kentya6/swift,gribozavr/swift,jopamer/swift,stephentyrone/swift,austinzheng/swift,jtbandes/swift,arvedviehweger/swift,aschwaighofer/swift,SwiftAndroid/swift,khizkhiz/swift,cbrentharris/swift,codestergit/swift,KrishMunot/swift,johnno1962d/swift,milseman/swift,karwa/swift,lorentey/swift,jtbandes/swift,uasys/swift,Ivacker/swift,devincoughlin/swift,huonw/swift,aschwaighofer/swift,gribozavr/swift,milseman/swift,harlanhaskins/swift,dduan/swift,frootloops/swift,khizkhiz/swift,kusl/swift,therealbnut/swift,ben-ng/swift,sdulal/swift,apple/swift,tkremenek/swift,huonw/swift,kentya6/swift,shajrawi/swift,kusl/swift,glessard/swift,emilstahl/swift,swiftix/swift,xedin/swift,gottesmm/swift,roambotics/swift,allevato/swift,tkremenek/swift,gribozavr/swift,russbishop/swift,gregomni/swift,felix91gr/swift,brentdax/swift,adrfer/swift,dduan/swift,johnno1962d/swift,gmilos/swift,karwa/swift,MukeshKumarS/Swift,djwbrown/swift,kusl/swift,ben-ng/swift,sdulal/swift,benlangmuir/swift,SwiftAndroid/swift,slavapestov/swift,johnno1962d/swift,xwu/swift,manavgabhawala/swift,practicalswift/swift,emilstahl/swift,danielmartin/swift,therealbnut/swift,Ivacker/swift,JGiola/swift,modocache/swift,natecook1000/swift,johnno1962d/swift,hooman/swift,tjw/swift,airspeedswift/swift,russbishop/swift,alblue/swift,jckarter/swift,gregomni/swift,jopamer/swift,shahmishal/swift,hughbe/swift,deyton/swift,manavgabhawala/swift,apple/swift,huonw/swift,frootloops/swift,return/swift,calebd/swift,felix91gr/swift,frootloops/swift,gribozavr/swift,slavapestov/swift,gmilos/swift,calebd/swift,xwu/swift,arvedviehweger/swift,sschiau/swift,MukeshKumarS/Swift,MukeshKumarS/Swift,felix91gr/swift,arvedviehweger/swift,slavapestov/swift,gregomni/swift,allevato/swift,manavgabhawala/swift,Ivacker/swift,uasys/swift,khizkhiz/swift,harlanhaskins/swift,roambotics/swift,tkremenek/swift,jmgc/swift,calebd/swift,rudkx/swift,gregomni/swift,dduan/swift,russbishop/swift,swiftix/swift.old,jtbandes/swift,frootloops/swift,aschwaighofer/swift,gmilos/swift,djwbrown/swift,return/swift,cbrentharris/swift,kstaring/swift,frootloops/swift,Ivacker/swift,mightydeveloper/swift,ahoppen/swift,allevato/swift,shahmishal/swift,practicalswift/swift,tjw/swift,LeoShimonaka/swift,milseman/swift,LeoShimonaka/swift,ahoppen/swift,Jnosh/swift,tjw/swift,alblue/swift,swiftix/swift.old,practicalswift/swift,jmgc/swift,zisko/swift,natecook1000/swift,airspeedswift/swift,adrfer/swift,gregomni/swift,sschiau/swift,kperryua/swift,amraboelela/swift,sdulal/swift,codestergit/swift,codestergit/swift,cbrentharris/swift,lorentey/swift,sschiau/swift,tardieu/swift,austinzheng/swift,lorentey/swift,IngmarStein/swift,zisko/swift,glessard/swift,xwu/swift,swiftix/swift.old,therealbnut/swift,practicalswift/swift,arvedviehweger/swift,danielmartin/swift,LeoShimonaka/swift,rudkx/swift,kperryua/swift,calebd/swift,amraboelela/swift,amraboelela/swift,xedin/swift,russbishop/swift,glessard/swift,kstaring/swift,amraboelela/swift,hooman/swift,allevato/swift,airspeedswift/swift,jckarter/swift,rudkx/swift,austinzheng/swift,emilstahl/swift,sschiau/swift,russbishop/swift,modocache/swift,dduan/swift,CodaFi/swift,mightydeveloper/swift,calebd/swift,tinysun212/swift-windows,roambotics/swift,devincoughlin/swift,milseman/swift,arvedviehweger/swift,karwa/swift,jopamer/swift,gottesmm/swift,Jnosh/swift,jtbandes/swift,modocache/swift,tkremenek/swift,roambotics/swift,johnno1962d/swift,felix91gr/swift,KrishMunot/swift,jmgc/swift,jtbandes/swift,gmilos/swift,shahmishal/swift,JGiola/swift,Jnosh/swift,amraboelela/swift,Jnosh/swift,shajrawi/swift,alblue/swift,huonw/swift,nathawes/swift,shajrawi/swift,atrick/swift,Jnosh/swift,bitjammer/swift,johnno1962d/swift,shahmishal/swift,return/swift,lorentey/swift,kusl/swift,rudkx/swift,Ivacker/swift,shajrawi/swift,rudkx/swift,kusl/swift,jmgc/swift,stephentyrone/swift,aschwaighofer/swift,huonw/swift,ken0nek/swift,tinysun212/swift-windows,CodaFi/swift,kentya6/swift,uasys/swift,JaSpa/swift,bitjammer/swift,arvedviehweger/swift,Ivacker/swift,hughbe/swift,stephentyrone/swift,cbrentharris/swift,aschwaighofer/swift,devincoughlin/swift,tkremenek/swift,zisko/swift,OscarSwanros/swift,nathawes/swift,felix91gr/swift,kstaring/swift,SwiftAndroid/swift,devincoughlin/swift,IngmarStein/swift,JGiola/swift,xedin/swift,kusl/swift,jmgc/swift,MukeshKumarS/Swift,karwa/swift,devincoughlin/swift,sschiau/swift,khizkhiz/swift,kentya6/swift,xwu/swift,ben-ng/swift,airspeedswift/swift,emilstahl/swift,harlanhaskins/swift,hooman/swift,jmgc/swift,uasys/swift,devincoughlin/swift,zisko/swift,danielmartin/swift,benlangmuir/swift,sdulal/swift,jopamer/swift,stephentyrone/swift,khizkhiz/swift,IngmarStein/swift,jopamer/swift,therealbnut/swift,hughbe/swift,KrishMunot/swift,parkera/swift,jopamer/swift,gribozavr/swift,parkera/swift,uasys/swift,airspeedswift/swift,kstaring/swift,JaSpa/swift,modocache/swift,tardieu/swift,danielmartin/swift,swiftix/swift,JaSpa/swift,harlanhaskins/swift,mightydeveloper/swift,sschiau/swift,roambotics/swift,KrishMunot/swift,allevato/swift,russbishop/swift,atrick/swift,hughbe/swift,return/swift,roambotics/swift,danielmartin/swift,apple/swift,slavapestov/swift,austinzheng/swift,practicalswift/swift,cbrentharris/swift,tjw/swift,ahoppen/swift,hughbe/swift,djwbrown/swift,jopamer/swift,IngmarStein/swift,dduan/swift,tinysun212/swift-windows,slavapestov/swift,benlangmuir/swift,frootloops/swift,zisko/swift,kstaring/swift,CodaFi/swift,brentdax/swift,deyton/swift,alblue/swift,JaSpa/swift,KrishMunot/swift,ken0nek/swift,natecook1000/swift,karwa/swift,xedin/swift,nathawes/swift,alblue/swift,amraboelela/swift,kentya6/swift,atrick/swift,mightydeveloper/swift,amraboelela/swift,modocache/swift,JaSpa/swift,OscarSwanros/swift,johnno1962d/swift,bitjammer/swift,harlanhaskins/swift,kperryua/swift,nathawes/swift,OscarSwanros/swift,milseman/swift,LeoShimonaka/swift,kperryua/swift,CodaFi/swift,IngmarStein/swift,frootloops/swift,austinzheng/swift,jckarter/swift,kentya6/swift,ahoppen/swift,sschiau/swift,return/swift,jtbandes/swift,deyton/swift,return/swift,jckarter/swift,ahoppen/swift,codestergit/swift,modocache/swift,rudkx/swift,SwiftAndroid/swift,IngmarStein/swift,ben-ng/swift,kusl/swift,manavgabhawala/swift,adrfer/swift,lorentey/swift,benlangmuir/swift,sdulal/swift,LeoShimonaka/swift,adrfer/swift,parkera/swift,ken0nek/swift,shahmishal/swift,kstaring/swift,benlangmuir/swift,bitjammer/swift,JGiola/swift,JGiola/swift,tardieu/swift,gottesmm/swift,hooman/swift,gottesmm/swift,brentdax/swift,tjw/swift,MukeshKumarS/Swift,mightydeveloper/swift,codestergit/swift,natecook1000/swift,xedin/swift,CodaFi/swift,Ivacker/swift,stephentyrone/swift,tardieu/swift,tardieu/swift,aschwaighofer/swift,austinzheng/swift,manavgabhawala/swift,deyton/swift,airspeedswift/swift,felix91gr/swift,modocache/swift,ken0nek/swift,calebd/swift,jmgc/swift,milseman/swift,tkremenek/swift,lorentey/swift,JaSpa/swift,bitjammer/swift,slavapestov/swift,kperryua/swift,stephentyrone/swift,devincoughlin/swift,zisko/swift,OscarSwanros/swift,LeoShimonaka/swift,swiftix/swift,ken0nek/swift,codestergit/swift,shajrawi/swift,kperryua/swift,OscarSwanros/swift,IngmarStein/swift,shahmishal/swift,hughbe/swift,hooman/swift,JGiola/swift,natecook1000/swift,nathawes/swift,parkera/swift,ahoppen/swift,jckarter/swift,bitjammer/swift,uasys/swift,bitjammer/swift,gmilos/swift,swiftix/swift.old,glessard/swift,gribozavr/swift,tinysun212/swift-windows,dduan/swift,tardieu/swift,CodaFi/swift,kentya6/swift,uasys/swift,huonw/swift,khizkhiz/swift,kperryua/swift,kentya6/swift,gottesmm/swift,OscarSwanros/swift,danielmartin/swift,tkremenek/swift,parkera/swift